<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>外边距-合并现象</title>
    <style>
        .one {
            width: 100px;
            height: 100px;
            background-color: #666111;

            /* margin-bottom: 20px; */
            margin-bottom: 100px;
        }

        .two {
            width: 100px;
            height: 100px;
            background-color: #789;

            margin-top: 50px;
        }
    </style>
</head>
<body>
    <div class="one">one</div>
    <div class="two">two</div>
</body>
</html>